AB0606 NODULAR MUCINOSIS AS INITIAL PRESENTATION OF SYSTEMIC LUPUS ERYTHEMATOSUS
Authors: D. Zajdman Faitelson, M. Macedo Pérez, P. Rodríguez Henríquez, D. Guerrero Hernández, M. E. Vega Memije
Journal: Annals of the Rheumatic Diseases (2023)

<h3>Background</h3> Cutaneous mucinoses comprise a wide group of disorders characterized by aberrant accumulation of glycosaminoglycans between collagen bundles, that share clinical and histological characteristics, and are classified as primary and secondary [1-3]. Nodular mucinosis associated with lupus is a primary mucinosis first described in 1954 by Gold [4]. It is a distinctive but unusual cutaneous manifestation, with an incidence of 1.5%, that presents as asymptomatic, skin-colored papules or nodules on the trunk and upper extremities [2]. It can occur in patients with discoid lupus, subacute cutaneous lupus or systemic lupus erythematosus (SLE) (2,5,6). The temporal relationship with the development of SLE is variable, since in some cases it precedes it, while in others it occurs later or simultaneously, with clinical variations according to disease activity and antibody levels [6,7]. <h3>Objectives</h3> Describe an infrequent cutaneous manifestation of SLE. <h3>Methods</h3> We describe a case of nodular mucinosis as an isolated clinical manifestation of SLE in a middle aged woman, with clinical improvement with methotrexate therapy. <h3>Results</h3> A 67-year-old female patient presented with an 8-month history of multiple skin-colored, asymptomatic nodules in face, trunk and extremities. Some of the nodules had a central depression (Figure 1 A and B). The clinical examination was otherwise unremarkable. Histological analysis of a biopsy specimen showed a circumscribed, non-encapsulated neoformation in the reticular dermis, composed of spindle cells in a storiform pattern, mixed with hyalinized collagen fibers (Figure 1 C). Alcian blue staining confirmed the presence of abundant interstitial, superficial and deep mucin, thus integrating the diagnosis of nodular mucinosis (Figure 1 D). Laboratory tests were positive for antinuclear antibodies (1:1000, coarse speckled pattern), anti-double stranded DNA (47.1 IU/ml), anti-nucleosome, anti-SSA/Ro, anti-RNP, anti-Sm antibodies and lupus anticoagulant, with a lymphocyte count of 3.6 cells/mm3 and hypocomplementemia (C4 of 15 mg/dL). A final diagnosis of nodular mucinosis associated with SLE was made and treatment was started with hydroxychloroquine 200 mg/day and prednisone 1 mg/kg/day. Improvement of skin lesions was observed after the addition of methotrexate 15 mg/weekly. <h3>Conclusion</h3> Our case presents a challenge to the clinician due to the atypical presentation and the absence of other systemic symptoms of SLE, as well as histologic findings similar or almost identical to other cutaneous mucinoses. This case demonstrates the importance of thorough dermatologic examination, high suspicion and directed complementary studies for the correct interdisciplinary approach to this entity. <h3>References</h3> [1]Shekari AM, Ghiasi M, Ghasemi E, Kani ZA. Papulonodular mucinosis indicating systemic lupus erythematosus. Clin Exp Dermatol. 2009;34(8):e558-60. [2]Sonntag M, Lehmann P, Megahed M, Ruzicka T, Kuhn A. Papulonodular Mucinosis Associated with Subacute Cutaneous Lupus erythematosus. Dermatology. 2003;206(4):326-9. [3]Maruyama M, Miyauchi S, Hashimoto K. Massive cutaneous mucinosis associated with systemic lupus erythematosus. Br J Dermatol. 1997;137(3):450-3. [4]Gold SC. AN UNUSUAL PAPULAR ERUPTION ASSOCIATED WITH LUPUS ERYTHEMATOSUS. Br J Dermatol. 1954;66(12):429-33. [5]Rongioletti F, Rebora A. The new cutaneous mucinoses: A review with an up-to-date classification of cutaneous mucinoses. J Am Acad Dermatol. 1991;24(2):265-70. [6]Dallo C, Lee K, Cragun WC, Lee M. A Case of Papulonodular Mucinosis in a Patient With Systemic Lupus Erythematosus. Am J Dermatopathol. 2020;42(4):280-2. [7]Elkeeb L, Spicknall KE, Mutasim DF. Nodular cutaneous mucinosis associated with systemic lupus erythematosus. Int J Dermatol. 2014;53(11):1389-91. <h3>Acknowledgements:</h3> NIL. <h3>Disclosure of Interests</h3> None Declared.